CHANGES IN MECHANICAL TOLERANCE AND CHILLING SENSITIVITY OF RED DRUM (SCIAENOPUS-OCELLATUS) EMBRYOS DURING DEVELOPMENT

The effects of mechanical shock and thermal stress on red drum (Sciaen opus ocellatus) embryos at specific developmental stages were studied. The tolerance of red drum embryos to mechanical and chilling shocks d epended on the embryo's stage of development. Gastrulae stage was more susceptible to mechanical shock than the other developmental stages. However, a different ontogenetic tolerance pattern for chilling shock was observed. It is suggested that the embryonic developmental stage n eeds be considered in future studies on the cryopreservation of fish e mbryos.